weird behaviour?? Twitching?
So, for the past month, I've been extremely busy and hence neglected weekly water changes in my 100 gallons cichlid tank. However, I do have a strong filter with lots of media and live sand as substrate.
The fish were very active and lively with huge appetites despite the neglect. Today, I decided I'd do a vast water change because the water was getting cloudy due to their messiness during feeding time. I did an 80% water change (Yes, a bit risky but it was necessary) and the fish changed completely. Some males are at the top column, some other males are more active than the rest and "flaring" at other males (which is pretty normal behaviour for those specific two males), and then some females and male runts are twitching while most others are laying on the sand as if asleep but barely moving.
P.S they're not gasping for air or anything and I do realize they might be stressed but this is not the first time I do big water changes, although I have never seen them act like this.
Help? any ideas?